Code snippet which is included verbatim by the UNITY_BUILD feature just before every #include statement in the generated unity source files. For example:
set(before [[
#if !defined(NOMINMAX)
#define NOMINMAX
#endif
]])
set_target_properties(myTarget PROPERTIES
UNITY_BUILD_CODE_BEFORE_INCLUDE "${before}"
)
See also UNITY_BUILD_CODE_AFTER_INCLUDE.